Condensing apparatus



July 16, 1929. u. A. TADDIKEN CONDENSING APPARATUS Filed July 8, 1927 e;INVENTORA A U.^:rad,di|(en l Fu.. BY ce' ATTORNEY WITNESSES PatentedJuly 16,

UNITED sms ULRICH A. TADDIKEN,OF PHILADELPHIA,` PENNSYLVANIA, ASSIGNORTO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OFPENNSYL- VANIA.

coNnENsrNe APPARATUS.

application sied :muy e, 1927. semi No. 204,345.

My invention relates to heat exchangers and like apparatus, in whichcondensation, or in which ebullition and condensation take place, and ithas for an object to improve the etliciency of apparatus of thischaracter.

The air and other non-condensable gases, or vapors, which are present inthe gaseous media lpassed into heat exchangers, such as surfacecondensers and the like, not only preclude the possibility of obtaininga perfect vacuum, but also tend to retard circulation and topi-eventcomplete condensation of the condensable gases.

Condensation leaves the non-condensable on the condensing surface, fromwhence they must be removed by proper circulation. The quantityofnon-condensable gases to be so removed, of course, increases with theprogress of gaseous media through a nest of cooling' tubes, so that, inthe later stages of the process, the non-condensable gases, which arealso relatively7 poor conductors of heat, comprise va substantialproportion of the gaseous media present.

' Hence, toward the completion of the process of condensation, thenon-condensables, due to their low conductivity, tend to form aninsulating medium and to delay the condensation of the condensablevapors approaching the condensing surface, and thus, also to retardcirculation.

Furthermore, the non-condensable gases exert a pressure which directlyaffects the vacuum obtainable. According to Daltons law of partialpressures, the pressure within a condenser, for example, is the totalpres sure of the gaseous mixture, or the summation of the partialpressures due to each of the respective gaseous constituents.

For example, assume the temperature at any point within a condenser tobe 101O F., and that for each pound of steam there is present 1/4 of apound of air, a condition which is not uncommon. At 101O F. a pound ofsteam occupies 341 cubic feet. rIhis same space then, also contains 1/4of a pound of air. The pressure of steam at 1010 F. is approximately 2of mercury, which correspends to a vacuum of 29.92-2 or 27.92 inches. l

However, the partial pressure due to the air is .81 inchesof mercury.From Daltons law then', the total pressure is 2-l-.31 or 2.31 inches ofmercury, which corresponds to a vacuum of only 29.92-231 or 27.61inches.

.downflow condensers l With one pound of air per pound of steam, i

which is a possible condition, the pressure due to the air would be 1.24inches of Inercury, under the same circumstances, and the vacuum wouldonly be 26.68 inches. It will readily beseen, therefore, that thekpartial pressure of the air has a very appreciable effect upon thevacuum, and that every precausion should be taken to prevent the air andother non-condensable gases from accumulating, or concentrating iny anyp0rtion of a condenser. f

{Ifsome of the gaseous media which conta-ins a relatively highproportion of the noncondensable gases is removed. from an exchanger ofthe type described, the surface of n this portion of the exchangerbecomes more effective, due to the fact that` gaseous media containing alower proportion of non-condensable gases may reach this surface.

Furthermore, if the gaseous media, so removed, is introduced into theexchanger at some point where the proportion of noncondensable gases issomewhat lower, the proportion of non-condensable gases present in thegaseous media throughout the exchangerv becomes more uniform, the effectof the relatively low conductivity of these gases and of their partialpressures becomes less, and their concentration in certain regions. isavoided.

More particularly, therefore, an object o my invention is to providemeans for removing gaseous media from a portion of a condenser in whichthe proportion of non- Condensable gases is relativelyhigh and forpassing the media so removed into the condenser in some region where thenon-con densable gases are less concentrated, so that the mixturecontaining` lthe relatively high proportion of non-condensables may beassimilated by a larger volume of gaseous media having a somewhat lowercontentvof non-condensables.` y

Apparatus embodying features of my invention is shown in theaccompanying draw` ings, in which;

l Figs. 1 and 2 are transverse sections of Figs. 8 and 4 are transversesections ofradial-flow condensers; and, y

Fig. 5 is a detail view of a connection .for removing gaseous media fromthe condenser shown in Fig. 4. i

According to my invention, any suitable i media withdrawn from thecondenser has practically the same temperature as the condensate whichserves as the cooling` media for the auxiliary heat exchanger, and henceit is assured that the withdrawn gaseous media will pass through thisauxiliary heat exchanger and be recirculated through the nest ofcondensing tubes.

Referring now to the drawings for a better understanding` of myinvention, I show, in Fig. 1, a straight down-flow condenser 10,comprising a shell 11, having a motive fluid inlet 12,'and` providedwith a hotwell 13. rIhe nest of cooling tubes 14 is separated, by thelongitudinally-extending baffle 16, to provide a cooling chamber 17 forcooling the air and other non-condensable gases previous to theirremoval through the air removal connection 18.

rIhe operation of the apparatus thus far described is well understood,motive fluid exhaust being passed into the shell through the inlet 12,passes through the nest of cooling tubes 14 where the motive fluidexhaust is condensed. As the gaseous media progresses through the nest14, the continuous removal of the condensable vapors `by condensationleaves a progressively increasing proportion of airand othernoncondensable .gases in the nest of cooling tubes, with the resultthat, in the lower portions o-f the tube nest 14, there is a tendencyfor the non-condensables to collect, or to become somewhat concentrated.

In order to prevent this condition, I provide suitable fluid translatingapparatus here shown in the form of steam-operated ejectors 21, whichare disposed along the bottom of the condenser shell on either sideofthe hotwell'. One or more of these ejectors may be used, dependingupon conditions, but, preferably, one such ejector and its associatedconnection are disposed on each side ofthe hotwell 13. Since thefunction of each of these ejectors is the same, only one will bedescribed.

The ejector 21 is of the usual form and comprises an entraining chamber22, a steam jet 23 and a diffuser 24. The entraining chamber 22- isconnected with the lower portion of the tube nest 14 by the connection26, this connection 26 being protected from the rain of condensate by acowl, or the like, 27, so that during the operation of the ejector,gaseous media may be drawn under the cowl 27 and through the connection26 to the entraining chamber 22 of the ej ector,

from whence it is removed through the diffuser 24.

In order to recover the heat of the motive fluid which passes throughthe jet 23 to actuate the ejector 21, I connect the diffuser 24 to thesteam space of a suitable heat exchanger 29, which is of the surfacetype, and is provided with a longitudinally-extending baflle ,31 forpreventing gaseous media from by-passing from the diffuser 24, through aportion of the nest, and to the connection 32 which is provided for theremoval of .gaseous media.

The condensate removal pump 33, for

the main condenser is arranged to dischargey into the connection 34,which connects with the circulating system of heat exchanger 29, thecondensate being discharged from the heat exchanger 29 through theconnection 36. In this way, it is possible to recover the heat of themotive fluid which issues from the jet 23 of the ejector 21 and entrainsthe gaseous media in the entraining chamber 22. The entrained media,having practically the same temperature as the condensate, which is usedas cooling media in the exchanger 29, will, of course, not be condensedin the heat exchanger 29, but will pass around the baflle 3l and outfrom the heat exchanger 29 through the connection 32, from which itpases into the tube `nest 14 at somesuitable point, as at'the connection37. A baille 38 is arranged to. depend from above the connection 37 soas to protect the tubes of the nest 14, which are adjacent to theconnection 37, from any vibration which might be caused by the passageof gaseous 'media through this connection.

The condensate, after passing from the connection 36 of the heatexchanger 29, may be utilized in any suitable manner, as for boiler feedwater.`

The condenser shown in Fig. `2, and also the apparatus shown forremoving gaseous media from the tube nest 14,l are in all respectssimilar to the arrangement shown in Fig. 1, with the exception that theheat exchanger 29 is omitted. In this case the entraining fluid whichissues from the jet 23l of the ejector 21, as well as the gaseous mediawhich is entrained, is passedl directly from the diffuser 24 through theconnection 32 into the nest of tubes 14 the entraining fluid as well asany condensahle 'vapors in the'entrained fluid being condensed' in thenest 14.

In this case, the heat of the motive fluid which actuates the ejector 21is not recovered, but the general improvement in the operationv of thecondenser is brought about as before. The cost of this apparatus isAless than that shown in Fig.v 1, due tothe elimination of the heatexchanger 29;

In the arrangement shown'in Fig. 3, ar rae lOl) dial-flow condenser 40,comprising a shell 41, having a motive fluid exhaust inlet (not shown)is provided With a hotwell 43. A portion of the tubes of the nest 44 areseparated from the condensing portionof the nest by spaced plates 46 and47, to provide v a cooling chamber 48 for cooling theair and the othernon-condensable gases, previous to their removal through the air removalconnection 49. The inner side, or portion, of this chamber is closed bya rain plate'or the like, 51, which rests on the upper ends of theplates 47, While the lower 'portion of the plates 46 are secured to theshell, the space between the plates 46 and 47 providing aV passage forgaseous media from the condens-- ing portion of the'tube nest 44 tothecooling the cooling chamber 48 so that a portion of the gaseous media.Which enters the cooling chamber maybe removed bythe ejector 21 andreturned to the tube nest 44 through connection 53, which, in this case,is for convenience arranged to pass the media into the tube nest 44along a lower portion thereof. It will be observed 'that inasmuch asthis is a radial-flow condenser, the path of vapor travel issubstantially the same forgaseous media at any point about the peripheryof the nest of cooling tubes.

In Fig. 4, a radial-flow condenser 54, comprising a shell 55, having amotive fluid exhaust inlet 576, is provided `With a hotvvell 57. rIheair and non-'condensable gases are removed from the nest of coolingtubes 58 through the removal connection 59, Which is protected from therain of condensate bya rain plate 61.

In this form of apparatus, the connection 26 of the ejector 21 isconnected to relatively short, longitudinally-extending pipes 62, bymeans of the connections 63 and 64. These pipes 62 appear inlongitudinal elevation in Fig. 5, from which it Will be observed thatthe open ends of the pipes are undercut, or biased, so as to permitgaseous media to enter either end of these pipes and to pass therefrom,through the respective connections 63 and 64, to the connection 26,While the projecting' upper ends of the pipes serve to prevent condensedmedia from passing into these connections. The media Withdrawn by theejector, as Well as the entraining fluid, then passed from the ejectorthroughthe connection 66 and into the nest 58 for recirculation.

will be observedthat gaseous media is re-` moved only afterit has passedthrough a considerable portion ofthe nest of cooling tubes, and thus itis assured that the media so removed Will contain as large a content ofnon-condensables as Willfbe found in gaseous media in any portion of thecondenser, and that this media is re-introduced into the nest ofcondensing` tubes at the point Where the proportion of non-condensablegases Will be relatively loW. In this Way itis possible to provide formaintaining a more uniform condition throughout lthe nest of coolingtubes,this vbeing accomplished by mixing gaseous media having a highcontent of noncondensables with gaseous media having a relatively loWcontent of non-condensables. It will thus be seen that I have'providedmeans for preventing they non-condensable gases from concentrating inany portion'of a heat exchanger, and for assuring improved conditionsfor vapor flow and for maintaining the desired vacuum; A It will also beobvious that my invention may be embodied in existing forms ofcondensing apparatus Without any material alterationsin such apparatus.Y l i i Furthermore, the air removal vapparatus is left to function asbefore, so that it is assured that the proper conditions of flow will beobtainedin J[he vicinity of the air removal connection, which, ofcourse, Would not be the case if the ioiv of gaseous media Were merelyaccelerated byv this' apparatus in an endeavor to ypreventtheconcentration of the non-condens'able gases.

lVhile I have shown the heat exchanger29 only in connection with a.down-flow condenser, it will be understood that it is Within theprovince of my invention to `provide similar heat ,exchangersl forradial flow condensers. l v Y While I have shown my invention in severalforms, it will be obvious to those skilled in the art that it is not solimited, but is susceptible of various other` changes and modificationsWithout departing from the spirit thereof, and I desire, therefore, thatonly such limitations shall be placed thereupon as are imposed by theprior art or as are specifically set forth in the appended claims. I

What I claim is 1. The combination With a nest of tubes, of means fordirecting gaseous media through the nest, and means for re-circulatingsome of the media through the nest.

2. The combination with a nest of tubes, of means for directing gaseousrmedia through the nest, fluid translating means for withdrawinguncondensed media from the nest, and means for passing media dischargedby said fluid translating means into the nest.

In Fig. 4, as Well as in the other views, it 3. A device of the typedescribed comprisiso ing a shell having an inlet for oondensable gases,a nest of tubes within the shell, fluid translatingmeans connected tothe shell at a point remote from said inlet, and means providing apassage from the discharge of the fluid translating means to the nest oftubes. Y

4. The combination with a surface condenser comprising a shell having amotive fluid inlet, a nest of tubes kwithin the shell, and an olitakefor airl and non-condensable gases, of fluid translating means having aninlet in a path of vapor travel to said ofi'take, and means for passingmedia discharged by said fluid translating means to the nest of tubes.

5. The combination with a surface condenser comprising a shell having amotive fluid inlet, a nest of tubes within the shell, and an-offtake forair land non-condensable gases, of Huid translating means having aninlet in a path of vapor travel to said offtake, a passagef'or passingmedia discharged by said fluid translating means to the nest of tubes,and cooling means interposed in said passage.

6. The combination with a surface con` denser comprising a shell havinga motive fluid'inlet, a nest oftubes within the shell, a hotwell for theshell, and an offtalie for air and non-condensable gases, of fluidtranslating means having an inlet in a path of vapor travel to saidofftake, a passage for conducting media discharged by said fluidtranslating means to the nest of tubes, cooling means interposed in saidpassage, and means for supplying cooling media for said cooling meansfrom the hotwell.

v 7 The combination with -a tubular heat exchanger having a condensingportion and a eoolingportion arranged for passing gaseous mediatherethrough in series', of means 8. The combination with a tubular heatexchanger having a condensing portion and a cooling portion arranged forpassing gaseous media therethrough in series, of fluid en` trainingmeans for withdrawing gaseous media from the eduction side of thecondensing portion, means for recovering heat from the entraining fluid,and means for recirculating the withdrawn media through the condens ingportion.

9. The combination with a tubular heat exchanger having a condensingportion and a cooling portion arrangedfor passing gaseous mediatherethrough in series, of fluid entraining means for withdrawinggaseous media from the eduction side of the condensing portion, meansfor transferring heat from the entraining fluid to condensate from thecondensing portion, and means for recirculating the withdrawn mediathrough the condensing portion.

10. The combination with a tubular heat exchanger having a condensingportion and a cooling portion arranged for passing gaseous mediatherethrough in series, of an ofi'- take for removing air andnon-condensable gases from the cooling portion, and means forwithdrawing gaseous media Vfrom the region substantially between saidcondensing and said cooling portions and for diverting the media sowithdrawn away from both the condensing portion and the cooling portion.

In testimony whereof, I have hereunto subscriped my name this 23rd dayof June, 192

ULRICH A. TADDIKEN.

